Radium-226 Detection by Radon Emanation and Rapid Simultaneous Scintillation Counting Methods

Since its beginning the universe has been contaminated with a host of radioactive isotopes. Of these radioactive isotopes, many have completely decayed away due to their short half-lives. The remaining naturally occurring isotopes are members of long decay chains such as uranium-238, uranium-235 and thorium-232. The natural background radiation in the environment is primarily due to the decay of these remaining isotopes. This background radiation is normally harmless to the existance of life unless concentrated amounts are received. Because of its chemical compatibility with calcium, radioactive radium isotopes are the most health hazardous of all naturally occurring isotopes. Radium chemically replaces calcium in the body where it is then deposited in bone tissue. These acute deposits of radium can cause severe health effects. Radium enters the body through the food and water one consumes, water being the major source of radium to the system. Accurate detection of radium-226 and radium-228 (the major radioactive isotopes of radium) in water is a difficult, tedious and lengthy procedure. However, McCurdy and Mellor of Yankee Atomic Electric Company Environmental Laboratory have developed a new method which has a number of advantages over the present Environmental Protection Agency (EPA) Radon Emanation Method. Cost, labor and speed are only a few of these advantages. The new Rapid Simultaneous Scintillation Counting Method (RSSC) developed by McCurdy and Mellor and the Radon Emanation Method were used to analyze water samples for their radium-226 content. The methods were then compared in three separate categories: accuracy, precision and their ability to meet Federal Regulations. The objectives of this research are to establish the performance of each method, and to compare. the RSSC method to the Radon Emanation method in the mentioned categories for the detection of radium-226

Retrospektive Untersuchung der Erythrozyten-Glutathionperoxidase-Aktivitäten von Rinder-Patienten der Klinik für Wiederkäuer

Retrospectively almost 14,000 erythrocytes glutathione peroxidase (eGSHPx) activities of cattle from the clinic for ruminants of the Ludwig Maximilian University of Munich were geographically mapped. The eGSHPx is the most important indirect marker for the selenium supply of mammals. There are significant eGSHPx activity differences between the singular years. This might be conditional upon the different weather and therefore different forage plant growth and inclusion of selenium into the plant tissues. Furthermore there are significant differences between the age-groups and sexes: the most considerable difference existed in the age-group of the heifers and young bulls (100 until 720 days). The female animals performed considerably worse than their male contemporaries. In contrast, dairy cows performed better than the adult bulls. The postcode eGSHPx medians were worked out from the farm eGSHPx medians. The map primarily contains the region of South Bavaria (administrative districts of Swabia, Upper Bavaria, and Lower Bavaria) in Germany. From the map it can be seen that the selenium supply in the Northern Pre-Alps (as far as Munich) is marginally adequate whereas the selenium supply in the Bavarian Tertiary Hill Country (to the north of Munich until the Danube River) is adequate. Only 0.59 % of the postcodes eGSHPx medians were deficient (< 60 U eGSHPx/g Hb), 1.53 % low-marginal (≤ 100 U eGSHPx/g Hb) and 2.59 % marginal (≤ 130 U eGSHPx/g Hb). There were no significant linear correlations between the eGSHPx activity and other laboratory parameters. Furthermore the findings of the clinical examination undertaken on admission of cattle with an eGSHPx activity under 200 U/g Hb from farms with a median above 200 U/g Hb were analysed retrospectively. Two age groups with several eGSHPx groups were constituted that were each composed half of selenium deficients and half of control animals: “Calves younger than 100 days“ (< 200 U/g Hb: n = 200; ≤ 130 U/g Hb: n = 334; ≤ 100 U/g Hb: n = 220; < 60 U/g Hb: n = 84) and “cattle 100 days and older“ (< 200 U/g Hb: n = 226; ≤ 130 U/g Hb: n = 110; ≤ 100 U/g Hb: n = 70). This procedure should guarantee that these animals did not have a primary or nutritive selenium deficiency (belief: whole live stock affected by selenium deficiency) but a secondary selenium deficiency conditional upon the pathology. Significant results arose in the group of the “calves younger than 100 days“ in the parameters “posture“ (p = 0.0137 and 0.0355), “nutritional condition“ (p = 0.0148), and “intestine/abomasum“ (p = 0.0327). Some significant results arose from the age group of “cattle 100 days and older”, namely of the parameters “runting” (p = 0.0036, 0.0358, and 0.0203), “infectious diseases” (malignant catarrhal fever, bovine virus diarrhoea/mucosal disease, listeriosis, and paratuberculosis) (p = 0.0043), and “viral diseases” (malignant catarrhal fever and bovine virus diarrhoea/mucosal disease) (p = 0.0378). This indicates that only severe and protracted diseases lead to secondary selenium deficiency whereas acute diseases can be rebelled by primarily selenium sufficient cattle without sinking into deficiency at once. The selenium deficient calves’ significantly worse “posture” is probably attributable to the general physical frailty due to selenium deficiency

Demonstration of methods for analytical measurement of natural circulation flow in EBR-II

Statement of responsibility on title page reads: R. J. Witt and J. E. Meyer, Includes MIT technical contributions from J. I. Choi, D. D. Lanning, J. E. Meyer, A. L. Schor, R. J. Witt and R. D. Wittmeier.""February, 1986."Includes bibliographical references (leaf 44)Final project reportSupported by U.S. Dept. of Energy, Breeder Technology Program, Division of Educational Programs, Argonne National Laborator

Physical activity and clustered cardiovascular disease risk factors in young children: a cross-sectional study (the IDEFICS study)

&lt;p&gt;Background The relevance of physical activity (PA) for combating cardiovascular disease (CVD) risk in children has been highlighted, but to date there has been no large-scale study analyzing that association in children aged &#8804;9 years of age. This study sought to evaluate the associations between objectively-measured PA and clustered CVD risk factors in a large sample of European children, and to provide evidence for gender-specific recommendations of PA.&lt;/p&gt; &lt;p&gt;Methods Cross-sectional data from a longitudinal study in 16,224 children aged 2 to 9 were collected. Of these, 3,120 (1,016 between 2 to 6 years, 2,104 between 6 to 9 years) had sufficient data for inclusion in the current analyses. Two different age-specific and gender-specific clustered CVD risk scores associated with PA were determined. First, a CVD risk factor (CRF) continuous score was computed using the following variables: systolic blood pressure (SBP), total triglycerides (TG), total cholesterol (TC)/high-density lipoprotein cholesterol (HDL-c) ratio, homeostasis model assessment of insulin resistance (HOMA-IR), and sum of two skinfolds (score CRFs). Secondly, another CVD risk score was obtained for older children containing the score CRFs + the cardiorespiratory fitness variable (termed score CRFs + fit). Data used in the current analysis were derived from the IDEFICS (‘Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS’) study.&lt;/p&gt; &lt;p&gt;Results In boys &#60;6 years, the odds ratios (OR) for CVD risk were elevated in the least active quintile of PA (OR: 2.58) compared with the most active quintile as well as the second quintile for vigorous PA (OR: 2.91). Compared with the most active quintile, older children in the first, second and third quintiles had OR for CVD risk score CRFs + fit ranging from OR 2.69 to 5.40 in boys, and from OR 2.85 to 7.05 in girls.&lt;/p&gt; &lt;p&gt;Conclusions PA is important to protect against clustering of CVD risk factors in young children, being more consistent in those older than 6 years. Healthcare professionals should recommend around 60 and 85 min/day of moderate-to-vigorous PA, including 20 min/day of vigorous PA.&lt;/p&gt

Improving together: better science writing through peer learning

Science, in our case the climate and geosciences, is increasingly interdisciplinary. Scientists must therefore communicate across disciplinary boundaries. For this communication to be successful, scientists must write clearly and concisely, yet the historically poor standard of scientific writing does not seem to be improving. Scientific writing must improve, and the key to long-term improvement lies with the early-career scientist (ECS). Many interventions exist for an ECS to improve their writing, like style guides and courses. However, momentum is often difficult to maintain after these interventions are completed. Continuity is key to improving writing. This paper introduces the ClimateSnack project, which aims to motivate ECSs to develop and continue to improve their writing and communication skills. The project adopts a peer-learning framework where ECSs voluntarily form writing groups at different institutes around the world. The group members learn, discuss, and improve their writing skills together. Several ClimateSnack writing groups have formed. This paper examines why some of the groups have flourished and others have dissolved. We identify the challenges involved in making a writing group successful and effective, notably the leadership of self-organized groups, and both individual and institutional time management. Within some of the groups, peer learning clearly offers a powerful tool to improve writing as well as bringing other benefits, including improved general communication skills and increased confidence

Dual oscillator model of the respiratory neuronal network generating quantal slowing of respiratory rhythm

We developed a dual oscillator model to facilitate the understanding of dynamic interactions between the parafacial respiratory group (pFRG) and the preBötzinger complex (preBötC) neurons in the respiratory rhythm generation. Both neuronal groups were modeled as groups of 81 interconnected pacemaker neurons; the bursting cell model described by Butera and others [model 1 in Butera et al. (J Neurophysiol 81:382–397, 1999a)] were used to model the pacemaker neurons. We assumed (1) both pFRG and preBötC networks are rhythm generators, (2) preBötC receives excitatory inputs from pFRG, and pFRG receives inhibitory inputs from preBötC, and (3) persistent Na+ current conductance and synaptic current conductances are randomly distributed within each population. Our model could reproduce 1:1 coupling of bursting rhythms between pFRG and preBötC with the characteristic biphasic firing pattern of pFRG neurons, i.e., firings during pre-inspiratory and post-inspiratory phases. Compatible with experimental results, the model predicted the changes in firing pattern of pFRG neurons from biphasic expiratory to monophasic inspiratory, synchronous with preBötC neurons. Quantal slowing, a phenomena of prolonged respiratory period that jumps non-deterministically to integer multiples of the control period, was observed when the excitability of preBötC network decreased while strengths of synaptic connections between the two groups remained unchanged, suggesting that, in contrast to the earlier suggestions (Mellen et al., Neuron 37:821–826, 2003; Wittmeier et al., Proc Natl Acad Sci USA 105(46):18000–18005, 2008), quantal slowing could occur without suppressed or stochastic excitatory synaptic transmission. With a reduced excitability of preBötC network, the breakdown of synchronous bursting of preBötC neurons was predicted by simulation. We suggest that quantal slowing could result from a breakdown of synchronized bursting within the preBötC

Physical activity, obesity and cardiometabolic risk factors in 9- to 10-year-old UK children of white European, South Asian and black African-Caribbean origin: the Child Heart And health Study in England (CHASE)

Physical inactivity is implicated in unfavourable patterns of obesity and cardiometabolic risk in childhood. However, few studies have quantified these associations using objective physical activity measurements in children from different ethnic groups. We examined these associations in UK children of South Asian, black African-Caribbean and white European origin. This was a cross-sectional study of 2,049 primary school children in three UK cities, who had standardised anthropometric measurements, provided fasting blood samples and wore activity monitors for up to 7 days. Data were analysed using multilevel linear regression and allowing for measurement error. Overall physical activity levels showed strong inverse graded associations with adiposity markers (particularly sum of skinfold thicknesses), fasting insulin, HOMA insulin resistance, triacylglycerol and C-reactive protein; for an increase of 100 counts of physical activity per min of registered time, levels of these factors were 12.2% (95% CI 10.2-14.1%), 10.2% (95% CI 7.5-12.8%), 10.2% (95% CI 7.5-12.8%), 5.8% (95% CI 4.0-7.5%) and 19.2% (95% CI 13.9-24.2%) lower, respectively. Similar increments in physical activity levels were associated with lower diastolic blood pressure (1.0 mmHg, 95% CI 0.6-1.5 mmHg) and LDL-cholesterol (0.04 mmol/l, 95% CI 0.01-0.07 mmol/l), and higher HDL-cholesterol (0.02 mmol/l, 95% CI 0.01-0.04 mmol/l). Moreover, associations were broadly similar in strength in all ethnic groups. All associations between physical activity and cardiometabolic risk factors were reduced (albeit variably) after adjustment for adiposity. Objectively measured physical activity correlates at least as well with obesity and cardiometabolic risk factors in South Asian and African-Caribbean children as in white European children, suggesting that efforts to increase activity levels in such groups would have equally beneficial effect

Scaled deployment of Wolbachia to protect the community from dengue and other Aedes transmitted arboviruses.

Background: A number of new technologies are under development for the control of mosquito transmitted viruses, such as dengue, chikungunya and Zika that all require the release of modified mosquitoes into the environment. None of these technologies has been able to demonstrate evidence that they can be implemented at a scale beyond small pilots. Here we report the first successful citywide scaled deployment of Wolbachia in the northern Australian city of Townsville. Methods: The wMel strain of Wolbachia was backcrossed into a local Aedes aegypti genotype and mass reared mosquitoes were deployed as eggs using mosquito release containers (MRCs). In initial stages these releases were undertaken by program staff but in later stages this was replaced by direct community release including the development of a school program that saw children undertake releases. Mosquito monitoring was undertaken with Biogents Sentinel (BGS) traps and individual mosquitoes were screened for the presence of Wolbachia with a Taqman qPCR or LAMP diagnostic assay. Dengue case notifications from Queensland Health Communicable Disease Branch were used to track dengue cases in the city before and after release. Results: Wolbachia was successfully established into local Ae. aegypti mosquitoes across 66 km 2 in four stages over 28 months with full community support.  A feature of the program was the development of a scaled approach to community engagement. Wolbachia frequencies have remained stable since deployment and to date no local dengue transmission has been confirmed in any area of Townsville after Wolbachia has established, despite local transmission events every year for the prior 13 years and an epidemiological context of increasing imported cases. Conclusion: Deployment of Wolbachia into Ae. aegypti populations can be readily scaled to areas of ~60km 2 quickly and cost effectively and appears in this context to be effective at stopping local dengue transmission

Chaotic Signatures of Heart Rate Variability and Its Power Spectrum in Health, Aging and Heart Failure

A paradox regarding the classic power spectral analysis of heart rate variability (HRV) is whether the characteristic high- (HF) and low-frequency (LF) spectral peaks represent stochastic or chaotic phenomena. Resolution of this fundamental issue is key to unraveling the mechanisms of HRV, which is critical to its proper use as a noninvasive marker for cardiac mortality risk assessment and stratification in congestive heart failure (CHF) and other cardiac dysfunctions. However, conventional techniques of nonlinear time series analysis generally lack sufficient sensitivity, specificity and robustness to discriminate chaos from random noise, much less quantify the chaos level. Here, we apply a ‘litmus test’ for heartbeat chaos based on a novel noise titration assay which affords a robust, specific, time-resolved and quantitative measure of the relative chaos level. Noise titration of running short-segment Holter tachograms from healthy subjects revealed circadian-dependent (or sleep/wake-dependent) heartbeat chaos that was linked to the HF component (respiratory sinus arrhythmia). The relative ‘HF chaos’ levels were similar in young and elderly subjects despite proportional age-related decreases in HF and LF power. In contrast, the near-regular heartbeat in CHF patients was primarily nonchaotic except punctuated by undetected ectopic beats and other abnormal beats, causing transient chaos. Such profound circadian-, age- and CHF-dependent changes in the chaotic and spectral characteristics of HRV were accompanied by little changes in approximate entropy, a measure of signal irregularity. The salient chaotic signatures of HRV in these subject groups reveal distinct autonomic, cardiac, respiratory and circadian/sleep-wake mechanisms that distinguish health and aging from CHF